C. neoformans Cryptococcosis develops when a person breathes in the microscopic fungus found in soil or rotting wood infected with bird droppings, particularly pigeon droppings. Interaction with an infected person could also help transmit the virus. C. neoformans is the most frequent cryptococcosis infection. The likelihood of developing cryptococcosis is higher in patients who have received high doses of corticosteroids, organ transplant patients, cancer patients taking chemotherapy, and those with AIDS or HIV infection. Due to the worldwide spread of AIDS, cryptococcosis is currently one of the most prevalent life-threatening fungal diseases in these individuals.
Furthermore, C. neoformans Cryptococcosis is prevalent in both people and animals, although neither animal-to-human nor human-to-human transmission by respiratory droplets has been observed. There have been reports of transmission during organ transplantation when contaminated donor organs were used. Infection from incisions in the skin is uncommon but possible.